3OC6HSL-bound, active state.
I knew Leadbetter was involved:'
Directed evolution of Vibrio fischeri LuxR for increased sensitivity to a broad spectrum of acyl-homoserine lactones
Cynthia H. Collins 1 , Frances H. Arnold 1,2 and Jared R. Leadbetter 3 *
1 Biochemistry and Molecular Biophysics,
2 Division of Chemistry and Chemical Engineering,
3 Environmental Science and Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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Summary
LuxR-type transcriptional regulators play key roles in quorum-sensing systems that employ acyl-homoserine lactones (acyl-HSLs) as signal molecules. These proteins mediate quorum control by changing their interactions with RNA polymerase and DNA in response to binding their cognate acyl-HSL. The evolutionarily related LuxR-type proteins exhibit considerable diversity in primary sequence and in their response to acyl-HSLs having acyl groups of differing length and composition. Little is known about which residues determine acyl-HSL specificity, and less about the evolutionary time scales required to forge new ones. To begin to examine such issues, we have focused on the LuxR protein from Vibrio fischeri, which activates gene transcription in response to binding its cognate quorum signal, 3-oxohexanoyl-homoserine lactone (3OC6HSL). Libraries of luxR mutants were screened for variants exhibiting increased gene activation in response to octanoyl-HSL (C8HSL), with which wild-type LuxR interacts only weakly. Eight LuxR variants were identified that showed a 100-fold increase in sensitivity to C8HSL; these variants also displayed increased sensitivities to pentanoyl-HSL and tetradecanoyl-HSL, while maintaining a wild-type or greater response to 3OC6HSL. The most sensitive variants activated gene transcription as strongly with C8HSL as the wild type did with 3OC6HSL. With one exception, the amino acid residues involved were restricted to the N-terminal, 'signal-binding' domain of LuxR. These residue positions differed from critical positions previously identified via 'loss-of-function' mutagenesis. We have demonstrated that acyl-HSL-dependent quorum-sensing systems can evolve rapidly to respond to new acyl-HSLs, suggesting that there may be an evolutionary advantage to maintaining such plasticity.
www3.interscience.wiley.com/journal/118659647/abstract?CRETRY=1&SRETRY=0===================
A DIRECTED EVOLUTION: It is unfolding...........................
We are finding the evidence now, that is what we need. to right this sucker.
Just rereading more of the Singularity, and seeing the crossover theories of doing
such an inorganic experiment. Thinking this directed evolution can program
the biological into inorganic, thereby recreating man into no longer natural
but combined natural and part of earths geophysical domain.
It was the dna that was in the earths material that began man, not the meteorite
itself. it was the live preserved dna, that eventually evolved from its core, after the
earth cooled down. Here is where evolutionist get it wrong. We need to go
back to Erasmus Darwin, not the grandson. He tried to butt the system back
then. Lunar Society. He knew what was coming. Many have tried to right
the situation.
I am trying to find the botanists who knew about the uredines. there is a lichenous
gel that forms through the agrobacterium. Investigators of old works suppressed
shows the alternative to the scheme taken by Monsanto, Bayer etc........
Will get into that later, but, the uredines and the infection in the root of plants can
cause plant rust or if not corrected will continue to produce plant rust.
Seems Monsanto and others took a wrong turn there somewhere.
skyship